"They've been dead even the whole time, and we'll see what happens," Carroll said. "The edge right now isn't very significant. We just had to pick out someone who had to go next, and we're ready to do that if we have to."

The slim margin could mean a world of difference if USC is forced to look to its bench for a quarterback.

Carroll said the decision wasn't based solely on the two quarterbacks' on-field performance.

"We're just going on the information we have. This is an area that doesn't even have that much to do with the playing," Carroll said. "It's more the smooth transfer of the information, and translating the situation and putting yourself in the best situations. It just looks like there's just a little edge right now, and that's all there is to it."

Corp's mobility and Mustain's big game experience were not factors in the decision, Carroll said.

Mustain said he sensed Corp would be the No. 2 guy as USC heads into its opener at Virginia. Still, Mustain said he's pleased with his progression through camp.

"It's not too much of a surprise," Mustain said. "I thought I was much better in the fall than I was in the spring.

"Whether I advanced as much as he did, it doesn't appear so."

Corp's had the luxury of settling into a spot during game week, and he said it's helped him prepare for one of the toughest jobs in sports - being a backup quarterback.

"You just have to be ready and keep preparing like you're going to play," Corp said. "You can kind of settle into your role on the team and prepare like you need to and know how to."

Carroll was able to avoid making any drastic decisions with Mark Sanchez returning to practice on Monday.

Sanchez got final clearance to play Wednesday night.

"It felt good," Sanchez said. "I was cleared for Monday, but that was just for practice. Once they said I'd be able to play in the game, it was a big relief."

Carroll said neither Mustain nor Corp would be working with the service team anytime soon, electing to give the quarterbacks valuable time in the Trojan offense.

With Mustain third on the depth chart for now, he said he'll have to adjust to watching Sanchez and Corp do the bulk of the work.

"It's been different," Mustain said. "I just have to work on staying in it mentally, sticking with the call, doing the mental reps and executing when I get in there."

Despite being behind two quarterbacks, Mustain said he doesn't regret his decision to transfer from Arkansas to USC.

"I still have three years," he said. "That's a long time for a lot of things to happen."

Great Expectations

Wide receiver Patrick Turner came to USC regarded as one of the best prep players in his class, but since arriving, he's not lived up to the hype.

"I don't know if anyone ever comes here and does," Carroll said.

Still, Turner has one more year to use his superior physical skills, his size and his deft route running to cap off his career with a big season.

Turner and the rest of the receivers dealt with criticism last year over dropped balls and general lack of productivity. This year, though, and it could all be different.

"We're really anxious. It's a new season, and we're not even thinking about last year," Turner said. "We worked really hard over the summer, getting extra work with the quarterbacks.

"Criticism will come, and it doesn't even matter. People are going to think what they want to think. That's nothing."

Billed as the heir to Dwayne Jarrett and Mike Williams, Carroll said the Trojans haven't been forced to utilize Turner in a starring role.

"The guys who he followed all had extraordinary years right away," Carroll said. "Patrick was there always when we went to him, but we never leaned on him as much as we did with Mike and Dwayne."

But maybe in his final year, Turner will silence critics and assume his place as the "next" towering receiver to suit up for USC.

"He's got a chance to," Carroll said.

Extra Points

• Shareece Wright returned to practice in a larger capacity after participating in most of Tuesday's workout. Wright's been ailing with an injury to his hip flexor and abdomen.

"It feels good. This is the most I've done since I've been back out here," Wright said. "I felt good today, and I felt good when I woke up this morning.

"Now that I'm practicing, I have to make it on the plane healthy."

• The offense spent time working on goal line and short-yardage packages, using three tight ends in some sets.

• Speakers blasted music early in practice before pumping crowd noise into Howard Jones Field.